1. Field of the Invention
The present invention is directed to a coupling arrangement with a vibration reduction device and with a clutch device, wherein the vibration reduction device has at least one torsional vibration damper an input connected to a drive, and an output connected to the clutch device by which a connection between the vibration reduction device and a driven end is at least substantially produced in a first operating state, and this connection is at least substantially cancelled in a second operating state.
2. Description of the Prior Art
A coupling arrangement of this kind can be seen from DE 11 2006 002 111 T5. With regard to the vibration reduction device, the housing of this coupling arrangement formed with an impeller, a turbine, and stator that acts as a drive. The vibration reduction device has a torsional vibration damper with two damping units arranged with a radial offset relative to one another. The output of the torsional vibration damper is connected to a friction disk element carrier of the clutch device which can be brought into operative connection with a further friction disk element carrier of the clutch device via a plurality of friction disk elements. The further friction disk element carrier mentioned above, which has a connection to the turbine, is fastened to a hub that acts as driven end of the vibration reduction device and can have a rotational connection to a driven shaft, for example, a transmission input shaft.
Insofar as the first operating state mentioned above is present, the hydrodynamic circuit of the coupling arrangement serving as hydrodynamic torque converter is to be bridged by the clutch device, this hydrodynamic circuit being formed by the impeller, turbine, and stator. In this regard, while the torsional vibration damper serves to reduce torsional vibrations superimposed on the transmitted torque, it is incapable of having any effect with respect to excitations, the order of which depends on the cylinder number of an internal combustion engine responsible for transmitting a torque to the housing of the coupling arrangement.
To have an effect during excitations of this kind, a preferred vibration reduction device has a mass damper system. A vibration reduction device of this kind can be seen from DE 10 2011 076 790 A1, FIG. 3. However, in contrast to the previously discussed coupling arrangement, the clutch device in this case is arranged between the housing of the coupling arrangement and the vibration reduction device and is therefore connected to the input of the torsional vibration damper whose output is in operative connection with a driven end realized as torsional vibration damper hub. The mass damper system mentioned above is likewise connected to the output of the torsional vibration damper.
In torsional vibration dampers with a vibration reduction device whose output is connected to a mass damper system, there is the advantage of very minor rotational irregularities even under full load at very low speed, for example, at a speed of 1,000 revolutions per minute. However, against this advantage an appreciable rise in rotational irregularity is noted at higher speed, for example, within a speed range between 1,500 and 1,800 revolutions per minute. This rise in rotational irregularity is accompanied by sharply dropping deflection angles at the output of the torsional vibration damper, even when torsional vibrations are present at the input of the torsional vibration damper. This behavior of the torsional vibration damper whose output persists at least approximately in a vibration node is caused by effects stemming from the transmission arrangement. It is especially disadvantageous that the output of the torsional vibration damper dwells in a vibration node because the vibration excitations which would be urgently required for the functioning of damper masses of the mass damper system connected to the output of the damping device are lacking in this case. This applies particularly to the above-mentioned appreciable rise in rotational irregularity.
When the clutch device is arranged between the housing of the coupling arrangement and the vibration reduction device, there is a difference in speed between the excitations present at the drive and the excitations present at the mass damper system when the clutch device acts with slip; this has an influence on the resulting excitation order of the mass damper system. If the mass damper system were configured for compensation on a higher order, this would result in an impairment of the decoupling quality in all operating states in which there is no significant slip. Under these circumstances, the configuration of the mass damper system is problematic.